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1.
BJPsych Open ; 10(4): e125, 2024 Jun 03.
Artículo en Inglés | MEDLINE | ID: mdl-38826043

RESUMEN

BACKGROUND: The use of feedback to address gaps and reinforce skills is a key component of successful competency-based mental health and psychosocial support intervention training approaches. Competency-based feedback during training and supervision for personnel delivering psychological interventions is vital for safe and effective care. AIMS: For non-specialists trained in low-resource settings, there is a lack of standardised feedback systems. This study explores perspectives on competency-based feedback, using structured role-plays that are featured on the Ensuring Quality in Psychosocial and Mental Health Care (EQUIP) platform developed by the World Health Organization and United Nations Children's Fund. METHOD: Qualitative data were collected from supervisors, trainers and trainees from multiple EQUIP training sites (Ethiopia, Kenya, Lebanon, Peru and Uganda), from 18 key informant interviews and five focus group discussions (N = 41 participants). Qualitative analysis was conducted in Dedoose, using a codebook with deductively and inductively developed themes. RESULTS: Four main themes demonstrated how a competency-based structure enhanced the feedback process: (a) competency-based feedback was personalised and goal-specific, (b) competency-based feedback supported a feedback loop, (c) competency-based feedback supported a comfortable and objective feedback environment, and (d) competency-based feedback created greater opportunities for flexibility in training and supervision. CONCLUSIONS: A better understanding of the role of feedback supports the implementation of competency-based training that is systematic and effective for trainers and supervisors, which ultimately benefits the learning process for trainees.

2.
Int J Ment Health Syst ; 18(1): 21, 2024 May 30.
Artículo en Inglés | MEDLINE | ID: mdl-38812016

RESUMEN

BACKGROUND: In humanitarian settings, brief screening instruments for child psychological distress have potential to assist in assessing prevalence, monitoring outcomes, and identifying children and adolescents in most need of scarce resources, given few mental health professionals for diagnostic services. Yet, there are few validated screening tools available, particularly in Arabic. METHODS: We translated and adapted the Child Psychosocial Distress Screener (CPDS) and the Pediatric Symptom Checklist (PSC) and conducted a validation study with 85 adolescents (aged 10-15) in Lebanon. We assessed internal consistency; test-retest reliability; convergent validity between adolescent- and caregiver-report and between the two measures; ability to distinguish between clinical and non-clinical samples; and concurrent validity against psychiatrist interview using the Kiddie Schedule for Affective Disorders and Schizophrenia. RESULTS: The translated and adapted child-reported PSC-17 and PSC-35, and caregiver-reported PSC-35 all showed adequate internal consistency and test-retest reliability and high concurrent validity with psychiatrist interview and were able to distinguish between clinical and non-clinical samples. However, the caregiver-reported PSC-17 did not demonstrate adequate performance in this setting. Child-reported versions of the PSC outperformed caregiver-reported versions and the 35-item PSC scales showed stronger performance than 17-item scales. The CPDS showed adequate convergent validity with the PSC, ability to distinguish between clinical and non-clinical samples, and concurrent validity with psychiatrist interview. Internal consistency was low for the CPDS, likely due to the nature of the brief risk-screening tool. There were discrepancies between caregiver and child-reports, worthy of future investigation. For indication of any diagnosis requiring treatment, we recommend cut-offs of 5 for CPDS, 12 for child-reported PSC-17, 21 for child-reported PSC-35, and 26 for caregiver-reported PSC-35. CONCLUSIONS: The Arabic PSC and CPDS are reliable and valid instruments for use as primary screening tools in Lebanon. Further research is needed to understand discrepancies between adolescent and caregiver reports, and optimal methods of using multiple informants.

3.
Artículo en Inglés | MEDLINE | ID: mdl-38087061

RESUMEN

There has been an increase in the evaluation and implementation of non-specialist delivered psychological interventions to address unmet mental health needs in humanitarian emergencies. While randomized controlled trials (RCTs) provide important evidence about intervention impact, complementary qualitative process evaluations are essential to understand key implementation processes and inform future scaling up of the intervention. This study was conducted as part of an RCT of the Early Adolescents Skills for Emotions (EASE) psychological intervention for young adolescents with elevated psychological distress (predominantly with a Syrian refugee background) in Lebanon. Our aims were firstly to conduct a qualitative process evaluation to understand stakeholder experiences and perceived impact of the intervention and identify barriers and facilitators for implementation, and secondly to explore considerations for scaling up. Eleven key informant interviews and seven focus groups were conducted with 39 respondents including adolescent and caregiver participants, trainers, providers, outreach workers, and local stakeholders. Data were analyzed using inductive and deductive thematic analysis. Respondents perceived the intervention to be highly needed and reported improvements in adolescent mental health and wellbeing. Key implementation factors that have potential to influence engagement, adherence, and perceived impact included the socio-economic situation of families, mental health stigma, coordination within and between sectors (particularly for scaling up), embedding the intervention within existing service pathways, having clear quality and accountability processes including training and supervision for non-specialists, and sustainable funding. Our findings provide important context for understanding effectiveness outcomes of the RCT and highlights factors that need to be considered when implementing a mental health intervention on a larger scale in a complex crisis.

4.
Compr Psychiatry ; 127: 152424, 2023 11.
Artículo en Inglés | MEDLINE | ID: mdl-37748283

RESUMEN

BACKGROUND: There is a need for scalable evidence-based psychological interventions for young adolescents experiencing high levels of psychological distress in humanitarian settings and low- and middle-income countries. Poor mental health during adolescence presents a serious public health concern as it is a known predictor of persistent mental disorders in adulthood. This study evaluates the effectiveness of a new group-based intervention developed by the World Health Organization (Early Adolescent Skills for Emotions; EASE), implemented by non-specialists, to reduce young adolescents' psychological distress among mostly Syrian refugees in Lebanon. METHODS: We conducted a two-arm, single-blind, individually randomized group treatment trial. Adolescents aged 10 to 14 years who screened positive for psychological distress using the Pediatric Symptom Checklist (PSC) were randomly allocated to EASE or enhanced treatment as usual (ETAU) (1:1.6). ETAU consisted of a single scripted psycho-education home-visit session with the adolescent and their caregivers. EASE consists of seven group sessions with adolescents and three sessions with caregivers. The primary outcome was adolescent-reported psychological distress as measured with the PSC (internalizing, externalizing, and attentional symptoms). Secondary outcomes included depression, posttraumatic stress, well-being, functioning, and caregivers' parenting and distress. All outcomes were assessed at baseline, endline, and 3 months (primary time point) and 12 months follow-up. RESULTS: Due to the COVID-19 pandemic and other adversities in Lebanon at the time of this research, the study was prematurely terminated, resulting in an under-powered trial sample (n = 198 enrolled compared to n = 445 targeted). We screened 604 children for eligibility. The 198 enrolled adolescents were assigned to EASE (n = 80) and ETAU (n = 118), with retention rates between 76.1 and 88.4% across all timepoints. Intent-to-treat analyses demonstrated no between-group differences on any of the outcome measures between the EASE and ETAU. We did observe a significant improvement on the primary outcome equally in the EASE and ETAU groups (-0.90, 95% CI: -3.6, 1.8; p = .52), - a trend that was sustained at three months follow-up. Sub-group analyses, for those with higher depression symptoms at baseline, showed ETAU outperformed EASE on reducing depression symptoms (difference in mean change = 2.7, 95% CI: 0.1, 5.3; p = .04; d = 0.59) and internalizing problems (difference in mean change 1.0, 95% CI: 0.08, 1.9; p = .03; d = 0.56) . CONCLUSION: No conclusions can be drawn about the comparative effectiveness of the intervention given that the sample was underpowered as a result of early termination. Both EASE and single session psycho-education home visits resulted in meaningful improvements in reducing psychological distress. We did not identify any indications in the data suggesting that EASE was more effective than a single session family intervention in the context of the COVID-19 pandemic and other crises in Lebanon. Fully powered research is needed to evaluate the effectiveness of EASE.


Asunto(s)
COVID-19 , Distrés Psicológico , Humanos , Adolescente , Niño , Líbano/epidemiología , Método Simple Ciego , Pandemias , COVID-19/epidemiología
5.
Hum Brain Mapp ; 44(10): 3954-3971, 2023 07.
Artículo en Inglés | MEDLINE | ID: mdl-37219891

RESUMEN

The perception and imagery of landmarks activate similar content-dependent brain areas, including occipital and temporo-medial brain regions. However, how these areas interact during visual perception and imagery of scenes, especially when recollecting their spatial location, remains unknown. Here, we combined functional magnetic resonance imaging (fMRI), resting-state functional connectivity (rs-fc), and effective connectivity to assess spontaneous fluctuations and task-induced modulation of signals among regions entailing scene-processing, the primary visual area and the hippocampus (HC), responsible for the retrieval of stored information. First, we functionally defined the scene-selective regions, that is, the occipital place area (OPA), the retrosplenial complex (RSC) and the parahippocampal place area (PPA), by using the face/scene localizer, observing that two portions of the PPA-anterior and posterior PPA-were consistently activated in all subjects. Second, the rs-fc analysis (n = 77) revealed a connectivity pathway similar to the one described in macaques, showing separate connectivity routes linking the anterior PPA with RSC and HC, and the posterior PPA with OPA. Third, we used dynamic causal modelling to evaluate whether the dynamic couplings among these regions differ between perception and imagery of familiar landmarks during a fMRI task (n = 16). We found a positive effect of HC on RSC during the retrieval of imagined places and an effect of occipital regions on both RSC and pPPA during the perception of scenes. Overall, we propose that under similar functional architecture at rest, different neural interactions take place between regions in the occipito-temporal higher-level visual cortex and the HC, subserving scene perception and imagery.


Asunto(s)
Mapeo Encefálico , Neocórtex , Mapeo Encefálico/métodos , Lóbulo Occipital/fisiología , Lóbulo Temporal/fisiología , Percepción Visual/fisiología , Imagen por Resonancia Magnética , Estimulación Luminosa
6.
BMC Psychiatry ; 23(1): 131, 2023 03 01.
Artículo en Inglés | MEDLINE | ID: mdl-36858980

RESUMEN

BACKGROUND: Globally, there is a vast mental health treatment gap, whereby the majority of adolescents living in low- and middle-income countries requiring mental health services, do not have access to adequate care. To improve access, the World Health Organization (WHO) developed a range of interventions, designed to be low-cost and delivered by non-specialists. We conducted a two-arm, individually randomised group treatment feasibility trial of a new WHO group intervention for young adolescents with emotional distress ('Early Adolescent Skills for Emotions'; EASE) in Lebanon. METHOD: The aim of this study was to determine the feasibility of the intervention and study procedures. Adolescents aged 10 to 14 years were eligible to take part if they scored above a validated cut-off on the Child Psychosocial Distress Screener. Participants were randomized to EASE or enhanced treatment as usual (ETAU) control using a 1:1 ratio. EASE consisted of seven group sessions with adolescents and three sessions with caregivers. ETAU consisted of a single brief psychoeducation home visit. Child and caregiver outcomes were measured by blind assessors at baseline, endline (8 weeks post-randomisation), and three month follow-up (20 weeks post-randomisation), with the primary outcome measure being child psychological symptoms on the Pediatric Symptom Checklist. Qualitative interviews were conducted with adolescents (n = 13), caregivers (n = 17), facilitators (n = 6), trainers (n = 3), and outreach staff (n = 1) at endline to assess barriers and facilitators related to the feasibility and delivery of EASE and study procedures. RESULTS: Of 154 adolescents screened, 67 (43%) were eligible, completed baseline, and were randomized. Sixty adolescents (90%) completed endline assessments (31 EASE, 29 ETAU), and fifty-nine (88%) completed three-month assessments (29 EASE, 30 ETAU). Qualitatively, participants provided overall positive feedback about the intervention. Several challenges and suggestions for improvement were raised around logistics, intervention content, and acceptability of assessment measures. Implementation data highlighted challenges with intervention uptake and attendance. Outcome measures generally had strong psychometric properties (range: α = 0.77 to α = 87), however did not demonstrate change over time in either group. CONCLUSIONS: The EASE intervention and study procedures are acceptable and feasible for implementation with vulnerable adolescents in Lebanon, however several improvements are necessary prior to full-scale evaluation. TRIAL REGISTRATION: #ISRCTN60799626, retrospectively registered on 04/10/2022.


Asunto(s)
Distrés Psicológico , Intervención Psicosocial , Adolescente , Humanos , Niño , Estudios de Factibilidad , Líbano , Emociones
7.
PLoS Comput Biol ; 18(12): e1009988, 2022 12.
Artículo en Inglés | MEDLINE | ID: mdl-36574458

RESUMEN

During resting-state EEG recordings, alpha activity is more prominent over the posterior cortex in eyes-closed (EC) conditions compared to eyes-open (EO). In this study, we characterized the difference in spectra between EO and EC conditions using dynamic causal modelling. Specifically, we investigated the role of intrinsic and extrinsic connectivity-within the visual cortex-in generating EC-EO alpha power differences over posterior electrodes. The primary visual cortex (V1) and the bilateral middle temporal visual areas (V5) were equipped with bidirectional extrinsic connections using a canonical microcircuit. The states of four intrinsically coupled subpopulations-within each occipital source-were also modelled. Using Bayesian model selection, we tested whether modulations of the intrinsic connections in V1, V5 or extrinsic connections (or a combination thereof) provided the best evidence for the data. In addition, using parametric empirical Bayes (PEB), we estimated group averages under the winning model. Bayesian model selection showed that the winning model contained both extrinsic connectivity modulations, as well as intrinsic connectivity modulations in all sources. The PEB analysis revealed increased extrinsic connectivity during EC. Overall, we found a reduction in the inhibitory intrinsic connections during EC. The results suggest that the intrinsic modulations in V5 played the most important role in producing EC-EO alpha differences, suggesting an intrinsic disinhibition in higher order visual cortex, during EC resting state.


Asunto(s)
Corteza Visual , Teorema de Bayes , Corteza Visual/fisiología , Corteza Cerebral , Ojo , Modelos Teóricos , Imagen por Resonancia Magnética/métodos , Electroencefalografía/métodos
8.
Neurobiol Pain ; 12: 100100, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36051490

RESUMEN

Chronic migraine is characterised by persistent headaches for >15 days per month; the intensity of the pain is fluctuating over time. Here, we explored the dynamic interplay of connectivity patterns between regions known to be related to pain processing and their relation to the ongoing dynamic pain experience. We recorded EEG from 80 sessions (20 chronic migraine patients in 4 separate sessions of 25 min). The patients were asked to continuously rate the intensity of their endogenous headache. On different time-windows, a dynamic causal model (DCM) of cross spectral responses was inverted to estimate connectivity strengths. For each patient and session, the evolving dynamics of effective connectivity were related to pain intensities and to pain intensity changes by using a Bayesian linear model. Hierarchical Bayesian modelling was further used to examine which connectivity-pain relations are consistent across sessions and across patients. The results reflect the multi-facetted clinical picture of the disease. Across all sessions, each patient with chronic migraine exhibited a distinct pattern of pain intensity-related cortical connectivity. The diversity of the individual findings are accompanied by inconsistent relations between the connectivity parameters and pain intensity or pain intensity changes at group level. This suggests a rejection of the idea of a common neuronal core problem for chronic migraine.

9.
Trials ; 23(1): 778, 2022 Sep 14.
Artículo en Inglés | MEDLINE | ID: mdl-36104820

RESUMEN

BACKGROUND: The management of cognitive impairment is an important goal in the treatment of multiple sclerosis (MS). While cognitive rehabilitation has been proven to be effective in improving cognitive performance in MS, research in the elderly indicates a higher effectiveness of combined cognitive-motor rehabilitation. Here, we present the protocol of a randomised controlled clinical trial to assess whether a combined cognitive-motor telerehabilitation programme is more effective in improving working memory than only cognitive or motor training. METHODS/DESIGN: The CoMoTeMS-trial is a two-centre, randomised, controlled and blinded clinical trial. A total of 90 patients with MS will receive 12 weeks of either a combined cognitive-motor telerehabilitation programme or only cognitive or motor training. The primary outcome is a change in the digit span backwards. Secondary outcomes are other cognitive changes (Brief International Cognitive Assessment for Multiple Sclerosis and Backward Corsi), Expanded Disability Status Scale (EDSS), 6-Min Walk Test, 25-Foot Walk Test, 9-Hole Peg Test, anxiety and depression, fatigue, quality of life, cognitive and physical activity level, electroencephalography and magnetic resonance imaging of the brain. DISCUSSION: We hypothesise that the improvement in digit span backwards after 12 weeks of treatment will be significantly higher in the group treated with the combined cognitive-motor telerehabilitation programme, compared to the groups receiving only cognitive and only motor training. TRIAL REGISTRATION: ClinicalTrials.gov NCT05355389. Registered on 2 May 2022.


Asunto(s)
Esclerosis Múltiple , Telerrehabilitación , Anciano , Cognición , Fatiga , Humanos , Esclerosis Múltiple/psicología , Calidad de Vida , Ensayos Clínicos Controlados Aleatorios como Asunto , Telerrehabilitación/métodos
10.
BMJ Open ; 12(4): e058101, 2022 04 20.
Artículo en Inglés | MEDLINE | ID: mdl-35443961

RESUMEN

INTRODUCTION: The World Health Organization's (WHO) scalable psychological interventions, such as Problem Management Plus (PM+) and Step-by-Step (SbS) are designed to be cost-effective non-specialist delivered interventions to reduce symptoms of common mental disorders, such as anxiety, depression and post-traumatic stress disorder (PTSD). The STRENGTHS consortium aims to evaluate the effectiveness, cost-effectiveness and implementation of the individual format of PM+ and its group version (gPM+), as well as of the digital SbS intervention among Syrian refugees in seven countries in Europe and the Middle East. This is a study protocol for a prospective individual participant data (IPD) meta-analysis to evaluate (1) overall effectiveness and cost-effectiveness and (2) treatment moderators of PM+, gPM+ and SbS with Syrian refugees. METHODS AND ANALYSIS: Five pilot randomised controlled trials (RCTs) and seven fully powered RCTs conducted within STRENGTHS will be combined into one IPD meta-analytic dataset. The RCTs include Syrian refugees of 18 years and above with elevated psychological distress (Kessler Psychological Distress Scale (K10>15)) and impaired daily functioning (WHO Disability Assessment Schedule 2.0 (WHODAS 2.0>16)). Participants are randomised into the intervention or care as usual control group, and complete follow-up assessments at 1-week, 3-month and 12-month follow-up. Primary outcomes are symptoms of depression and anxiety (25-item Hopkins Symptom Checklist). Secondary outcomes include daily functioning (WHODAS 2.0), PTSD symptoms (PTSD Checklist for DSM-5) and self-identified problems (PSYCHLOPS). We will conduct a one-stage IPD meta-analysis using linear mixed models. Quality of evidence will be assessed using the GRADE approach, and the economic evaluation approach will be assessed using the CHEC-list. ETHICS AND DISSEMINATION: Local ethical approval has been obtained for each RCT. This IPD meta-analysis does not require ethical approval. The results of this study will be published in international peer-reviewed journals.


Asunto(s)
Refugiados , Trastornos por Estrés Postraumático , Humanos , Metaanálisis como Asunto , Medio Oriente , Intervención Psicosocial , Ensayos Clínicos Controlados Aleatorios como Asunto , Refugiados/psicología , Trastornos por Estrés Postraumático/psicología , Siria
11.
Brain Struct Funct ; 227(5): 1831-1842, 2022 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-35312868

RESUMEN

Successful navigation relies on the ability to identify, perceive, and correctly process the spatial structure of a scene. It is well known that visual mental imagery plays a crucial role in navigation. Indeed, cortical regions encoding navigationally relevant information are also active during mental imagery of navigational scenes. However, it remains unknown whether their intrinsic activity and connectivity reflect the individuals' ability to imagine a scene. Here, we primarily investigated the intrinsic causal interactions among scene-selective brain regions such as Parahipoccampal Place Area (PPA), Retrosplenial Complex, and Occipital Place Area (OPA) using Dynamic Causal Modelling for resting-state functional magnetic resonance data. Second, we tested whether resting-state effective connectivity parameters among scene-selective regions could reflect individual differences in mental imagery in our sample, as assessed by the self-reported Vividness of Visual Imagery Questionnaire. We found an inhibitory influence of occipito-medial on temporal regions, and an excitatory influence of more anterior on more medial and posterior brain regions. Moreover, we found that a key role in imagery is played by the connection strength from OPA to PPA, especially in the left hemisphere, since the influence of the signal between these scene-selective regions positively correlated with good mental imagery ability. Our investigation contributes to the understanding of the complexity of the causal interaction among brain regions involved in navigation and provides new insight in understanding how an essential ability, such as mental imagery, can be explained by the intrinsic fluctuation of brain signal.


Asunto(s)
Mapeo Encefálico , Individualidad , Encéfalo , Humanos , Imagen por Resonancia Magnética
12.
Neuroimage ; 231: 117841, 2021 05 01.
Artículo en Inglés | MEDLINE | ID: mdl-33577934

RESUMEN

In recent years, specific cortical networks have been proposed to be crucial for sustaining consciousness, including the posterior hot zone and frontoparietal resting state networks (RSN). Here, we computationally evaluate the relative contributions of three RSNs - the default mode network (DMN), the salience network (SAL), and the central executive network (CEN) - to consciousness and its loss during propofol anaesthesia. Specifically, we use dynamic causal modelling (DCM) of 10 min of high-density EEG recordings (N = 10, 4 males) obtained during behavioural responsiveness, unconsciousness and post-anaesthetic recovery to characterise differences in effective connectivity within frontal areas, the posterior 'hot zone', frontoparietal connections, and between-RSN connections. We estimate - for the first time - a large DCM model (LAR) of resting EEG, combining the three RSNs into a rich club of interconnectivity. Consistent with the hot zone theory, our findings demonstrate reductions in inter-RSN connectivity in the parietal cortex. Within the DMN itself, the strongest reductions are in feed-forward frontoparietal and parietal connections at the precuneus node. Within the SAL and CEN, loss of consciousness generates small increases in bidirectional connectivity. Using novel DCM leave-one-out cross-validation, we show that the most consistent out-of-sample predictions of the state of consciousness come from a key set of frontoparietal connections. This finding also generalises to unseen data collected during post-anaesthetic recovery. Our findings provide new, computational evidence for the importance of the posterior hot zone in explaining the loss of consciousness, highlighting also the distinct role of frontoparietal connectivity in underpinning conscious responsiveness, and consequently, suggest a dissociation between the mechanisms most prominently associated with explaining the contrast between conscious awareness and unconsciousness, and those maintaining consciousness.


Asunto(s)
Anestésicos/administración & dosificación , Red en Modo Predeterminado/fisiología , Lóbulo Frontal/fisiología , Redes Neurales de la Computación , Lóbulo Parietal/fisiología , Inconsciencia/fisiopatología , Estado de Conciencia/efectos de los fármacos , Estado de Conciencia/fisiología , Red en Modo Predeterminado/efectos de los fármacos , Electroencefalografía/efectos de los fármacos , Electroencefalografía/métodos , Femenino , Lóbulo Frontal/efectos de los fármacos , Humanos , Masculino , Lóbulo Parietal/efectos de los fármacos , Propofol/administración & dosificación , Inconsciencia/inducido químicamente , Adulto Joven
13.
Epilepsia Open ; 5(4): 537-549, 2020 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-33336125

RESUMEN

OBJECTIVE: To quantify whole-brain functional organization after complete hemispherotomy, characterizing unexplored plasticity pathways and the conscious level of the dissected hemispheres. METHODS: Evaluation with multimodal magnetic resonance imaging in two pediatric patients undergoing right hemispherotomy including complete callosotomy with a perithalamic section. Regional cerebral blood flow and fMRI network connectivity assessed the functional integrity of both hemispheres after surgery. The level of consciousness was tested by means of a support vector machine classifier which compared the intrinsic organization of the dissected hemispheres with those of patients suffering from disorders of consciousness. RESULTS: After hemispherotomy, both patients showed typical daily functionality. We found no interhemispheric transfer of functional connectivity in either patient as predicted by the operation. The healthy left hemispheres displayed focal blood hyperperfusion in motor and limbic areas, with preserved network-level organization. Unexpectedly, the disconnected right hemispheres showed sustained network organization despite low regional cerebral blood flow. Subcortically, functional connectivity was increased in the left thalamo-cortical loop and between the cerebelli. One patient further showed unusual ipsilateral right cerebello-cortical connectivity, which was explained by the mediation of the vascular system. The healthy left hemisphere had higher probability to be classified as in a minimally conscious state compared to the isolated right hemisphere. SIGNIFICANCE: Complete hemispherotomy leads to a lateralized whole-brain organization, with the remaining hemisphere claiming most of the brain's energetic reserves supported by subcortical structures. Our results further underline the contribution of nonneuronal vascular signals on contralateral connectivity, shedding light on the nature of network organization in the isolated tissue. The disconnected hemisphere is characterized by a level of consciousness which is necessary but insufficient for conscious processing, paving the way for more specific inquiries about its role in awareness in the absence of behavioral output.

14.
Brain Sci ; 10(10)2020 Oct 07.
Artículo en Inglés | MEDLINE | ID: mdl-33036334

RESUMEN

A consistent finding in migraine is reduced cortical habituation to repetitive sensory stimuli. This study investigated brain dynamics underlying the atypical habituation to painful stimuli in interictal migraine. We investigated modulations in effective connectivity between the sources of laser evoked potentials (LEPs) from a first to final block of trigeminal LEPs using dynamic causal modelling (DCM) in a group of 23 migraine patients and 20 controls. Additionally, we looked whether the strength of dynamical connections in the migrainous brain is initially different. The examined network consisted of the secondary somatosensory areas (lS2, rS2), insulae (lIns, rIns), anterior cingulate cortex (ACC), contralateral primary somatosensory cortex (lS1), and a hidden source assumed to represent the thalamus. Results suggest that migraine patients show initially heightened communication between lS1 and the thalamus, in both directions. After repetitive stimulations, connection strengths from the thalamus to all somatosensory areas habituated in controls whereas this was not apparent in migraine. Together with further abnormalities in initial connectivity strengths and modulations between the thalamus and the insulae, these results are in line with altered thalamo-cortical network dynamics in migraine. Group differences in connectivity from and to the insulae including interhemispheric connections, suggests an important role of the insulae.

15.
Front Psychiatry ; 11: 212, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32265759

RESUMEN

Armed conflict leads to increased risk of emotional distress among children and adolescents, and increased exposure to significant daily stressors such as poverty and community and family violence. Unfortunately, these increased risks usually occur in the context of largely unavailable mental health services. There is growing empirical support that evidence-based treatment techniques can be adapted and delivered by non-specialists with high fidelity and effectiveness. However, in order to improve feasibility, applicability, and outcomes, appropriate cultural and contextual adaptation is essential when delivering in different settings and cultures. This paper reports the adaptation process conducted on a new World Health Organization psychological intervention-Early Adolescent Skills for Emotions (EASE)-for use in the north of Lebanon. Lebanon is a middle-income country that hosts the largest number of refugees per capita globally. We conducted: i) a scoping review of literature on mental health in Lebanon, with a focus on Syrian refugees; ii) a rapid qualitative assessment with adolescents, caregivers, community members, and health professionals; iii) cognitive interviews regarding the applicability of EASE materials; iv) a psychologist review to reach optimal and consistent Arabic translation of key terms; v) "mock sessions" of the intervention with field staff and clinical psychology experts; vi) gathering feedback from the Training of Trainers workshop, and subsequent implementation of practice sessions; and vii) gathering feedback from the Training of Facilitators workshop, and subsequent implementation of practice sessions. Several changes were implemented to the materials-some were Lebanon-specific cultural adaptations, while others were incorporated into original materials as they were considered relevant for all contexts of adversity. Overall, our experience with adaptation of the EASE program in Lebanon is promising and indicates the acceptability and feasibility of a brief, non-specialist delivered intervention for adolescents and caregivers. The study informs the wider field of global mental health in terms of opportunities and challenges of adapting and implementing low-intensity psychological interventions in settings of low resources and high adversity.

16.
Neuroimage ; 213: 116699, 2020 06.
Artículo en Inglés | MEDLINE | ID: mdl-32179104

RESUMEN

Global signal (GS) is an ubiquitous construct in resting state functional magnetic resonance imaging (rs-fMRI), associated to nuisance, but containing by definition most of the neuronal signal. Global signal regression (GSR) effectively removes the impact of physiological noise and other artifacts, but at the same time it alters correlational patterns in unpredicted ways. Performing GSR taking into account the underlying physiology (mainly the blood arrival time) has been proven to be beneficial. From these observations we aimed to: 1) characterize the effect of GSR on network-level functional connectivity in a large dataset; 2) assess the complementary role of global signal and vessels; and 3) use the framework of partial information decomposition to further look into the joint dynamics of the global signal and vessels, and their respective influence on the dynamics of cortical areas. We observe that GSR affects intrinsic connectivity networks in the connectome in a non-uniform way. Furthermore, by estimating the predictive information of blood flow and the global signal using partial information decomposition, we observe that both signals are present in different amounts across intrinsic connectivity networks. Simulations showed that differences in blood arrival time can largely explain this phenomenon, while using hemodynamic and calcium mouse recordings we were able to confirm the presence of vascular effects, as calcium recordings lack hemodynamic information. With these results we confirm network-specific effects of GSR and the importance of taking blood flow into account for improving de-noising methods. Additionally, and beyond the mere issue of data denoising, we quantify the diverse and complementary effect of global and vessel BOLD signals on the dynamics of cortical areas.


Asunto(s)
Artefactos , Encéfalo/fisiología , Circulación Cerebrovascular/fisiología , Conectoma/métodos , Procesamiento de Imagen Asistido por Computador/métodos , Humanos , Imagen por Resonancia Magnética/métodos
17.
Brain Res ; 1733: 146728, 2020 04 15.
Artículo en Inglés | MEDLINE | ID: mdl-32067965

RESUMEN

INTRODUCTION: Despite the worldwide increase in prevalence of chronic pain and the subsequent scientific interest, researchers studying the brain and brain mechanisms in pain patients have not yet clearly identified the exact underlying mechanisms. Quantifying the neuronal interactions in electrophysiological data could help us gain insight into the complexity of chronic pain. Therefore, the aim of this study is to examine how different underlying pain states affect the processing of nociceptive information. METHODS: Twenty healthy participants, 20 patients with non-neuropathic low back-related leg pain and 20 patients with neuropathic failed back surgery syndrome received nociceptive electrical stimulation at the right sural nerve with simultaneous electroencephalographic recordings. Dynamic Causal Modeling (DCM) was used to infer hidden neuronal states within a Bayesian framework. RESULTS: Pain intensity ratings and stimulus intensity of the nociceptive stimuli did not differ between groups. Compared to healthy participants, both patient groups had the same winning DCM model, with an additional forward and backward connection between the somatosensory cortex and right dorsolateral prefrontal cortex. DISCUSSION: The additional neuronal connection with the prefrontal cortex as seen in both pain patient groups could be a reflection of the higher attention towards pain in pain patients and might be explained by the higher levels of pain catastrophizing in these patients. CONCLUSION: In contrast to the similar pain intensity ratings of an acute nociceptive electrical stimulus between pain patients and healthy participants, the brain is processing these stimuli in a different way.


Asunto(s)
Encéfalo/fisiopatología , Neuralgia/fisiopatología , Nocicepción/fisiología , Adulto , Estimulación Eléctrica , Electroencefalografía , Femenino , Humanos , Masculino , Persona de Mediana Edad , Corteza Prefrontal/fisiopatología , Corteza Somatosensorial/fisiopatología , Nervio Sural/fisiopatología , Adulto Joven
18.
Neuroimage ; 208: 116435, 2020 03.
Artículo en Inglés | MEDLINE | ID: mdl-31816423

RESUMEN

The influence of global BOLD fluctuations on resting state functional connectivity in fMRI data remains a topic of debate, with little consensus. In this study, we assessed the effects of global signal regression (GSR) on effective connectivity within and between resting state networks (RSNs) - as estimated with dynamic causal modelling (DCM) for resting state fMRI (rsfMRI). DCM incorporates a forward (generative) model that quantifies the contribution of different types of noise (including global measurement noise), effective connectivity, and (neuro)vascular processes to functional connectivity measurements. DCM analyses were applied to two different designs; namely, longitudinal and cross-sectional designs. In the modelling of longitudinal designs, we considered four extensive longitudinal resting state fMRI datasets with a total number of 20 subjects. In the analysis of cross-sectional designs, we used rsfMRI data from 361 subjects from the Human Connectome Project. We hypothesized that (1) GSR would have no discernible impact on effective connectivity estimated with DCM, and (2) GSR would be reflected in the parameters representing global measurement noise. Additionally, we performed comparative analyses of information gain with and without GSR. Our results showed negligible to small effects of GSR on effective connectivity within small (separately estimated) RSNs. However, although the effect sizes were small, there was substantial to conclusive evidence for an effect of GSR on connectivity parameters. For between-network connectivity, we found two important effects: the effect of GSR on between-network effective connectivity (averaged over all connections) was negligible to small, while the effect of GSR on individual connections was non-negligible. In the cross-sectional (but not in the longitudinal) data, some connections showed substantial to conclusive evidence for an effect of GSR. Contrary to our expectations, we found either no effect (in the longitudinal designs) or a non-specific (cross-sectional design) effect of GSR on parameters characterising (global) measurement noise. Data without GSR were found to be more informative than data with GSR; however, in small resting state networks the precision of posterior estimates was greater after GSR. In conclusion, GSR is a minor concern in DCM studies; however, quantitative interpretation of between-network connections (as opposed to average between-network connectivity) and noise parameters should be treated with some caution. The Kullback-Leibler divergence of the posterior from the prior (i.e., information gain) - together with the precision of posterior estimates - might offer a useful measure to assess the appropriateness of GSR in resting state fMRI.


Asunto(s)
Corteza Cerebral/fisiología , Conectoma/métodos , Imagen por Resonancia Magnética/métodos , Red Nerviosa/fisiología , Adulto , Corteza Cerebral/diagnóstico por imagen , Conectoma/normas , Estudios Transversales , Femenino , Humanos , Estudios Longitudinales , Imagen por Resonancia Magnética/normas , Masculino , Red Nerviosa/diagnóstico por imagen , Adulto Joven
19.
Neuroimage ; 206: 116326, 2020 02 01.
Artículo en Inglés | MEDLINE | ID: mdl-31678499

RESUMEN

This analysis explores the effective connectivity of the cerebellum with the cerebral cortex during the generation of correct sequences of social and non-social events, using dynamic causal modelling (DCM). Our hypothesis is that during human evolution, the cerebellum's function evolved from a mere coordinator of fluent sequences of motions and actions, to an interpreter of action sequences without overt movements that are important for social understanding. This requires efficient neural communication between the cerebellum and cerebral cortex. In a functional magnetic resonance imaging (fMRI) study, participants generated the correct chronological order of (non-)social events, including stories involving mechanical and social scripts, and true or false beliefs. Across all stories, a DCM analysis of these data revealed, as predicted, bidirectional (closed-loop) connections linking the bilateral posterior cerebellum with the bilateral temporo-parietal junction (TPJ) associated with behavior understanding, and this connectivity pattern was almost entirely significant. There was also a unidirectional connection from the right posterior cerebellum to the precuneus, but no direct connections with the dorsomedial prefrontal cortex (dmPFC). Moreover, all connections emanating from the bilateral posterior cerebellum were negative, indicative of some kind of error signal. Within the cerebral cortex, there were unidirectional connections from the bilateral TPJ to the dmPFC, as well as bidirectional connections between the precuneus and dmPFC, and between the bilateral TPJ. These results confirm that the effective connectivity between the posterior cerebellum and mentalizing areas in the cerebral cortex play a critical role in the understanding and construction of the correct order of social and non-social action sequences.


Asunto(s)
Cerebelo/diagnóstico por imagen , Corteza Cerebral/diagnóstico por imagen , Percepción Social , Teorema de Bayes , Cerebelo/fisiología , Corteza Cerebral/fisiología , Femenino , Neuroimagen Funcional , Humanos , Imagen por Resonancia Magnética , Masculino , Mentalización , Vías Nerviosas , Lóbulo Parietal/diagnóstico por imagen , Lóbulo Parietal/fisiología , Corteza Prefrontal/diagnóstico por imagen , Corteza Prefrontal/fisiología , Lóbulo Temporal/diagnóstico por imagen , Lóbulo Temporal/fisiología
20.
Neuroimage ; 207: 116369, 2020 02 15.
Artículo en Inglés | MEDLINE | ID: mdl-31747561

RESUMEN

Previous studies have characterized the brain regions involved in encoding monetary reward and punishment outcomes. The question of how this information is integrated across brain regions has received less attention. Here, we investigated changes in effective connectivity related to the processing of positive and negative monetary outcomes using functional magnetic resonance imaging data from the Human Connectome Project. Specifically, subjects engaged in a card guessing game which could yield win, loss, or neutral outcomes. A general linear model was used to define a network of regions involved in win and loss outcome processing, including anterior insula, anterior cingulate cortex, and ventral striatum. Dynamic causal modelling (DCM) was implemented to study between-region couplings and outcome-related modulations thereof within this network. In addition, we explored the relation between effective connectivity patterns and choice behavior in the gambling task. Parametric empirical Bayesian modelling was conducted for group-level inferences of both DCM and the choice behavior. Behaviorally, both win and loss outcomes increased the probability of choice switches in subsequent gambles. In terms of connectivity, win outcomes were associated with increased extrinsic connectivity across the network, while loss outcomes featured a balance between increased and decreased extrinsic connectivity. Moreover, self-inhibitory connections tended to decrease for both win and loss outcomes. Interestingly, a substantial discrepancy was observed for occipital cortex connectivity, which was characterized by intrinsic disinhibition in loss but not in win trials. The observed differences in effective connectivity during the processing of positive and negative outcomes, despite similarities in average regional activity and choice behavior, highlight the value of exploring network dynamics in the context of incentive manipulations.


Asunto(s)
Conducta/fisiología , Red Nerviosa/fisiología , Recompensa , Estriado Ventral/fisiología , Adulto , Conectoma/métodos , Femenino , Juego de Azar , Humanos , Imagen por Resonancia Magnética/métodos , Masculino
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